US patent application 2011/0187185 discloses an electric traction chain for an automobile, including an onboard rechargeable power source, a static converter capable of generating a three-phase voltage system connected by input to the rechargeable power source, a three phase electric motor supplied with power by the three-phase voltage system generated by the static converter, wherein an external electric power source is connectable to the stator windings of the motor to enable recharging of the onboard power source across the static converter.
An issue with this electric traction chain is that it is not very practical for charging by means of a one phase power line in case the electrical machine—the electromotor—comprises permanent magnets in the rotor, because the inductors of the stator are not equally charged. With permanent magnets in the rotor, this causes the rotor to move.